Hollow motor apparatuses and associated systems and methods

ABSTRACT

Hollow motor apparatuses and associated systems and methods for manufacturing hollow motor apparatuses may be provided. In one implementation, a hollow motor apparatus may include a rotor assembly rotatable about a rotation axis, a stator assembly positioned adjacent to, and coaxially with, the rotor assembly, and a bearing assembly configured to maintain a position of the rotor assembly relative to the stator assembly. The rotor assembly may include an inner portion disposed around an opening configured to receive and to rotate at least a portion of a payload. The bearing assembly may be disposed outside of the inner portion of the rotor assembly.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 15/729,518, filed Oct. 10, 2017, which is acontinuation application of International Application No.PCT/CN2017/078678, filed Mar. 29, 2017, both of which are hereinincorporated by reference in their entireties.

TECHNICAL FIELD

The present technology is directed generally to hollow motorapparatuses, associated systems, and methods for manufacturing the same.More particularly, embodiments of the present technology relate to ahollow motor that can accommodate a component (e.g., a light source, alens, and/or other suitable components) therein.

BACKGROUND

Traditionally, an electrical motor includes a stator and a rotorrotatable relative to the stator. The rotor includes a magnet and thestator includes a set of winding wires. When an electrical currentpasses through the winding wires, a magnetic field is formed which thenrotates the rotor relative to the stator. There are various structuraldesigns for the electrical motor. For example, an “inner-rotor” typeelectrical motor has a rotor positioned generally internal to thestator. On the contrary, an “outer-rotor” type electrical motor has arotor positioned generally external to the stator. In general,traditional electrical motors are not suitable for positioningadditional rotatable components/elements therein at least because theydo not have sufficient space to accommodate such components/elements.Due to a need for driving a rotatable component positioned in anelectrical motor, it is beneficial to have an improved apparatus orsystem to address this need.

SUMMARY

The following summary is provided for the convenience of the reader andidentifies several representative embodiments of the disclosedtechnology. Generally speaking, the present technology provides animproved hollow motor apparatus that enables a user to position acomponent (an element, a module, and/or other suitable devices) thereinsuch that the component can rotate with a rotor assembly of the hollowmotor apparatus. For example, embodiments of the present technologyinclude a hollow electrical motor that has an interior space (or anopening) to accommodate one or more optical components (e.g., lenses,prisms, and/or other suitable optical devices) and/or a light source(e.g., a light source emitting visible or non-visible radiation, a laseremitter, and/or other suitable light sources).

In some embodiments, the optical component rotates with the rotorassembly and the light source does not rotate with the rotor assembly(e.g., the light source is fixedly coupled to a stator assembly of thehollow electrical motor). In some embodiments, both the opticalcomponent and the light source can rotate with the rotor assembly. Insuch embodiments, various aspects of the light emitted from the lightsource (e.g., by changing an emitting angle, a color, a brightness,and/or other suitable parameters) can be configured or adjusted so as toperform scanning, ranging, signifying different statuses of the UAVand/or performing other functions.

By rotating the optical component, the user can direct the light emittedfrom the light source in desirable directions. For example, the presenttechnology enables the user to generate a set of focused light rays (ora set of parallel light rays, in other embodiments). The focused lightrays (e.g., laser rays) can be used to transmit information to the userof a moveable apparatus (e.g., a vehicle or a UAV) coupled to the hollowelectrical motor. In some embodiments, the focused light rays can beused for ranging and scanning objects or obstacles in a surroundingenvironment of the moveable apparatus. The hollow electrical motor canalso be used to drive the moveable apparatus (e.g., by coupling to androtating a propeller). Accordingly, embodiments of the presenttechnology provide an improved hollow electrical motor that can (1)rotate optical components positioned in a compact hollow structure(e.g., a range finder or a Lidar system); and (2) drive a UAV andsignify a status of the UAV.

Representative embodiments of the present technology include a hollowmotor apparatus having a rotor assembly, a stator assembly, and apositioning component (e.g., a bearing assembly) positioned to maintaina location of the rotor assembly relative to the stator assembly. Therotor assembly is positioned to be rotatable about a rotation axis(e.g., an axis passing through the rotation center of the rotor assemblywhen it is rotating). The rotor assembly has an inner portion and anouter portion. The inner portion circumferentially faces the rotationaxis and bounds, at least in part, an interior chamber for accommodatinga component to be positioned inside the hollow motor apparatus. Thebearing assembly is positioned external to the inner portion of therotor assembly (e.g., farther away from the rotation axis). In someembodiments, the bearing assembly is operably (e.g., rotatably) coupledto the rotor assembly and the stator assembly. The bearing assembly canrotate relative to the rotor assembly and/or the stator assembly whilemaintaining the relative locations of the rotor/stator assemblies. Thebearing assembly can include a bearing, a rolling ball, a rolling pin,and/or other suitable devices. In some embodiments, additionalcomponents, such as a set of lens or prisms, can be positioned in theinterior space and coupled to the rotor assembly.

Some embodiments of the present technology provide a hollow apparatushaving an annular structure, an optical component, and a drivingassembly. The annular structure (which can include, for example, ahollow cylinder, a pipe-shaped structure, and/or other suitable hollowstructures) is positioned to be rotatable about a rotation axis. Theannular structure has an inner portion, which circumferentially facesthe rotation axis and bounds (or defines), at least in part, an interiorchamber (or an opening). The interior chamber is used to accommodate theoptical component, which is carried by the annular structure. Thedriving assembly is configured to rotate the annular structure (with theoptical component) so as to position the optical component at aparticular (angular) location (e.g., such that the optical component candirect light from a light source to a desirable target area). In someembodiments, the driving assembly can be a stator assembly and theannular structure can be a rotor assembly. In some embodiments, thedriving assembly can include a driving component (e.g., a motor or ameans that can rotate other components). In some embodiments, thedriving component can be coupled to the rotor assembly via a positioningcomponent (e.g., a belt, a gear, a pulley and/or other suitable devices)that is positioned/configured to maintain a location of the annularstructure relative to the driving assembly.

Some embodiments of the present technology can be implemented as methodsfor manufacturing and/or using a hollow motor apparatus. Arepresentative method can include, inter alia, (1) performing arotation-balance analysis on an optical component to generate ananalysis result; (2) at least partially based on the analysis result,weight-balancing the optical component; (3) positioning the opticalcomponent in an interior chamber defined at least in part by an innerportion of a rotor assembly; (4) coupling the optical component to therotor assembly; (5) coupling the rotor assembly to a bearing assembly;and (6) coupling the bearing assembly to a stator assembly. The bearingassembly is positioned external to the inner portion of the rotorassembly so as to maintain a location (e.g., a radial location relativeto a rotation axis of the rotor assembly) of the rotor assembly relativeto the stator assembly. Methods and systems in accordance withembodiments of the present technology can include any one or acombination of any of the foregoing elements described above.

The present technology also includes a method for balancing a rotatablecomponent to be positioned inside the hollow motor apparatus. The methodincludes, for example, (1) determining the shape and the density of therotatable component; (2) performing a weight-balance test at multipleplanes (which are generally perpendicular to a rotation axis about whichthe rotatable component rotates); (3) consolidating the results of theweight-balance test for the multiple planes; (4) determining acounterweight (or a portion of the rotatable component that needs to beremoved) to be coupled to the rotatable component (or to a rotorassembly coupled to the rotatable component) and an expected location ofthe counterweight; and (5) positioning the counterweight at the expectedlocation. In some embodiments, the method can be used to balancemultiple rotatable components. In such embodiments, the multiplerotatable components can rotate at different rotational speeds (e.g.,driven by different motors or driven by different gears coupled to onemotor).

In some embodiments, the present technology enables a user to determinea combination of rotatable components to be installed in a hollow motorapparatus so as to perform desirable functions described above. Forexample, a user can select a combination of a focusing lens, a coloringlens, and a point light source. In this embodiment, the selectedcombination can generate a focused light beam with a specific color. Asanother example, the user can select two asymmetrical lenses and a laserlight source. In this embodiment, the selected combination can generatemultiple laser rays that can be properly distributed in a target area(e.g., the two asymmetrical lenses can rotate at different rotationalspeeds and directions, so as to achieve this goal). In such embodiments,the reflected laser rays can be received and then be used to measure thedistance between the target area and the laser light source (or asurface feature, contour, terrain, and/or other suitable parameters ofthe target area). Having a proper distribution of laser rays in thetarget area can be beneficial at because this can effectively increasethe accuracy of the related measurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram illustrating a UAV having a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 1B is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 1C is a partially schematic cross-sectional view illustrating apropeller and a hollow motor assembly configured in accordance withrepresentative embodiments of the present technology.

FIG. 1D is a partially schematic cross-sectional view illustrating twohollow motor assemblies in a Lidar system configured in accordance withrepresentative embodiments of the present technology.

FIG. 2 is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 3A is a cross sectional view illustrating components of a hollowmotor assembly configured in accordance with representative embodimentsof the present technology.

FIG. 3B is a cross-sectional view taken along line A-A of FIG. 3Aillustrating components of a hollow motor assembly configured inaccordance with representative embodiments of the present technology.

FIG. 4A is a top view illustrating components of a hollow motor assemblyconfigured in accordance with representative embodiments of the presenttechnology.

FIG. 4B is a cross-sectional view taken along line B-B of FIG. 4Aillustrating components of a hollow motor assembly configured inaccordance with representative embodiments of the present technology.

FIG. 4C is a cross-sectional view taken along line B-B of FIG. 4Aillustrating components of another hollow motor assembly configured inaccordance with representative embodiments of the present technology.

FIG. 4D is an isometric, schematic view illustrating components of ahollow motor assembly configured in accordance with representativeembodiments of the present technology.

FIG. 5A is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 5B is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 5C is an isometric view illustrating components of another hollowmotor assembly configured in accordance with representative embodimentsof the present technology.

FIG. 5D includes an end view illustrating components of yet anotherhollow motor assembly configured in accordance with representativeembodiments of the present technology.

FIG. 5E is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIGS. 5F, 5G, and 5H are schematic diagrams illustrating methods forpre-positioning or pre-tightening in accordance with representativeembodiments of the present technology.

FIG. 6A is an isometric view illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 6B is an isometric view illustrating a stator assembly configuredin accordance with representative embodiments of the present technology.

FIG. 6C is an isometric view illustrating another stator assemblyconfigured in accordance with representative embodiments of the presenttechnology.

FIG. 6D is an isometric view illustrating a stator segment configured inaccordance with representative embodiments of the present technology.

FIG. 7A is a top view illustrating components of a hollow assemblyconfigured in accordance with representative embodiments of the presenttechnology.

FIG. 7B is an isometric view illustrating components of a hollowassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 7C is an isometric view illustrating components of another hollowassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 8 is a top view illustrating components of yet another hollowassembly configured in accordance with representative embodiments of thepresent technology.

FIG. 9A is a schematic diagram illustrating components of a hollow motorassembly configured in accordance with representative embodiments of thepresent technology.

FIGS. 9B and 9C are isometric views illustrating multiple opticalcomponents configured in accordance with embodiments of the presenttechnology.

FIG. 10 is a schematic diagram illustrating multiple optical componentsconfigured in accordance with embodiments of the present technology.

FIGS. 11A and 11B are schematic diagrams illustrating a counterweightconfigured in accordance with representative embodiments of the presenttechnology.

FIG. 12 is a schematic diagram illustrating a rotation-balance analysisfor an optical component configured in accordance with representativeembodiments of the present technology.

FIG. 13 is a flowchart illustrating a method in accordance withrepresentative embodiments of the present technology.

FIG. 14 is a flowchart illustrating a method in accordance withrepresentative embodiments of the present technology.

DETAILED DESCRIPTION 1. Overview

The present technology is directed generally to hollow motor apparatusesand associated systems and methods. A representative hollow motorapparatus in accordance with the present technology can be used to (1)provide power to move a moveable device (e.g., a UAV); (2) visuallypresent indications or signals that relate to a status of the moveabledevice (e.g., an indication that the UAV is low on battery power) orother information that an operator of the moveable device wants toconvey; and/or (3) detect the status of an object outside the moveabledevice. For example, the operator can use a laser light sourcepositioned in the hollow apparatus to detect the existence of (or thedistance to) an obstacle outside the moveable device. A representativehollow motor apparatus in accordance with the present technologyincludes a hollow structure that can be used to accommodate a componentor payload (e.g., a lens, a prism, a light source, and/or other suitabledevices) that (1) is positioned inside the hollow motor apparatus, and(2) is rotatable with a rotor assembly (or an annular structure) of thehollow motor apparatus. Via this arrangement, the moveable device canhave additional functions (e.g., visually presenting information and/ordetecting an object) without requiring extra space for installingadditional parts/components. In other words, the present technologyefficiently utilizes the interior space inside the hollow motorapparatus to make additional functions possible.

Several details describing structures or processes that are well-knownand often associated with electrical motors and corresponding systemsand subsystems, but that may unnecessarily obscure some significantaspects of the disclosed technology, are not set forth in the followingdescription for purposes of clarity. Moreover, although the followingdisclosure sets forth several embodiments of different aspects of thetechnology, several other embodiments can have different configurationsand/or different components than those described in this section.Accordingly, the technology may have other embodiments with additionalelements and/or without several of the elements described below withreference to FIGS. 1-13.

FIGS. 1-13 are provided to illustrate representative embodiments of thedisclosed technology. Unless provided for otherwise, the drawings arenot intended to limit the scope of the claims in the presentapplication. Many embodiments of the technology described below may takethe form of computer- or controller-executable instructions, includingroutines executed by a programmable computer or controller. Thoseskilled in the relevant art will appreciate that the technology can bepracticed on computer or controller systems other than those shown anddescribed below. The technology can be embodied in a special-purposecomputer or data processor that is specifically programmed, configuredor constructed to perform one or more of the computer-executableinstructions described below. Accordingly, the terms “computer” and“controller” as generally used herein refer to any suitable dataprocessor and can include Internet appliances and handheld devices(including palm-top computers, wearable computers, cellular or mobilephones, multi-processor systems, processor-based or programmableconsumer electronics, network computers, mini computers, a programmedcomputer chip, and the like).

Information handled by these computers and controllers can be presentedat any suitable display medium, including a CRT display or an LCD.Instructions for performing computer- or controller-executable tasks canbe stored in or on any suitable computer-readable medium, includinghardware, firmware or a combination of hardware and firmware.Instructions can be contained in any suitable memory device, including,for example, a flash drive, USB device, or other suitable medium. Inparticular embodiments, the term “component” can include hardware,firmware, or a set of instructions stored in a computer-readable medium.

2. Representative Embodiments

FIG. 1A is a schematic diagram illustrating a UAV 100 having a hollowmotor assembly 101 configured in accordance with representativeembodiments of the present technology. As shown in FIG. 1A, the UAV 100includes an airframe (or a main body) 106, a UAV controller 102 carriedby the UAV 100 and configured to control the UAV 100, a gimbal 103coupled to the airframe 106, and a UAV payload 104 coupled to andcarried by the gimbal 103. In some embodiments, the UAV payload 104 caninclude an imaging device. In particular embodiments, the imaging devicecan include an image camera (e.g., a camera that is configured tocapture video data, still data, or both). The camera can be sensitive towavelengths in any of a variety of suitable wavelength bands, includingvisual, ultraviolet, infrared or combinations thereof. In still furtherembodiments, the UAV payload 104 can include other types of sensors,other types of cargo (e.g., packages or other deliverables), or both. Inmany of these embodiments, the gimbal 103 supports the UAV payload 104in a way that allows the UAV payload 104 to be independently positionedrelative to the airframe 106. Accordingly, for example, when the UAVpayload 104 includes an imaging device, the imaging device can be movedrelative to the airframe 106 to track a target.

The airframe 106 can include a central portion 106 a and one or moreouter portions 106 b. In particular embodiments, the airframe 106 caninclude four outer portions 106 b (e.g., arms) that are spaced apartfrom each other as they extend away from the central portion 106 a. Inother embodiments, the airframe 106 can include other numbers of outerportions 106 b. In any of these embodiments, individual outer portions106 b can support one or more components of a propulsion system thatdrives the UAV 100. For example, individual arms can supportcorresponding individual motors 101 a that drive correspondingpropellers 105. The UAV controller 102 is configured to control the UAV100. In some embodiments, the UAV controller 102 can include a processorcoupled and configured to control the other components of the UAV 100.In some embodiments, the UAV controller 102 can be coupled to a storagecomponent that is configured to, permanently or temporarily, storeinformation associated with or generated by the UAV 100. In particularembodiments, the storage component can include a disk drive, a harddisk, a flash drive, a memory, or the like. As shown in FIG. 1A, the UAV100 can also include a hollow motor assembly 101 b configured to rotatea rotatable lens/prism of a range finding device/component (or a rangescanning device or a Lidar system). In some embodiments, the hollowmotor assembly 101 b can be carried by a vehicle (e.g., a self-drivingcar).

FIG. 1B is an isometric view illustrating components of a hollow motorassembly 101 configured in accordance with representative embodiments ofthe present technology. As shown in FIG. 1B, the hollow motor assembly101 includes a rotor assembly 107, a stator assembly 108, and apositioning component (e.g., a bearing assembly) 109. In someembodiments, the rotor assembly 107 includes a magnet 107 a and a magnetyoke 107 b coupled to the magnet 107 a. The rotor assembly 107 ispositioned/configured to rotate about a rotation axis R. The rotorassembly 107 includes an inner surface 116 that circumferentially facesor bounds an opening or an interior chamber 117. As noted in FIG. 1B, aradial direction and an angular direction can be defined at leastpartially based on the rotation axis R.

The stator assembly 108 can include a first stator portion 108 a and asecond stator portion 108 b positioned opposite to the first statorportion 108 a. The stator assembly 108 is not rotatable and is fixedlyattached to other components of the UAV 100 (e.g., a housing). When anelectrical current passes through a winding component (discussed infurther detail below with reference to FIG. 6E) of the stator assembly108, a magnetic field is formed, which moves the magnet 107 a. Bycontrolling the electrical current and the generated magnetic field, therotor assembly 107 can be rotated at various rotational speeds. In someembodiments, the stator assembly 108 can have any number of statorportions (such as illustrated in FIG. 1B), or can have a full annularstructure (such as discussed elsewhere herein).

The bearing assembly 109 is positioned adjacent to the rotor assembly107 and configured to maintain the (radial) location of the rotorassembly 107 relative to the stator assembly 108. In the illustratedembodiments, the bearing assembly 109 includes a bearing that can rotateabout a rotation axis A. Because the bearing assembly 109 can rotaterelative to the rotor assembly 107, it can effectively position therotor assembly 107 without unduly interfering with the rotation of therotor assembly 107. In the illustrated embodiment, the hollow motorassembly 101 further includes a guide rail (or protrusion) 115positioned adjacent to or as a part of the rotor assembly 107. In theillustrated embodiment, the guide rail 115 is positioned to facilitatemaintaining the location of the bearing assembly 109 relative to therotor assembly 107. In other embodiments, the guide rail 115 canimplemented as a protrusion extending from the bearing assembly 109. Insome embodiments, the guide rail 115 can also facilitate maintaining thelocation of the bearing assembly 109 relative to the stator assembly108.

FIG. 1C is a partially schematic cross-sectional view illustrating apropeller 105 and a hollow motor assembly 101 configured in accordancewith representative embodiments of the present technology. The propeller105 includes a first blade 110, a second blade 111 opposite to the firstblade 110, and a hub 112. When the propeller 105 is rotating, the outeredges of the first/second blades 110, 111 can together define arotational disk. The hollow motor assembly 101 includes a rotor assembly107 and a stator assembly 108 positioned external to the rotor assembly107. In this arrangement, the hollow motor assembly 101 is referred toas an “inner-rotor” motor. In other embodiments, however, the hollowmotor assembly 101 can be an “outer-rotor” motor (as discussed belowwith reference to FIG. 5E). In some embodiments, the stator assembly 108can be fixedly attached to other components (e.g., a housing) of the UAV100. The rotor assembly 107 can rotate relative to the stator assembly108. As shown, the rotor assembly 107 has an inner surface 116 thatcircumferentially faces or bounds an interior chamber (or interiorspace) 117. The interior chamber 117 is at least partially defined bythe inner surface 116 of the rotor assembly 107. The interior chamber117 can be used to accommodate one or more rotatable or non-rotatablecomponents.

As shown in FIG. 1C, an optical component, a transparent component orother suitable component 114 can be positioned in the interior chamber117 and coupled to the rotor assembly 107. When the rotor assembly 107rotates, the optical component 114 can rotate with the rotor assembly107. In some embodiments, the optical component 114 can include a lens,a prism, or a combination thereof. In the illustrated embodiment of FIG.1C, a light source 113 is positioned in the interior chamber 117 andcoupled to a non-rotatable component (e.g., a housing or the statorcomponent 108 of the UAV 100). The light source 113 is configured toemit light rays to the propeller 105 through the optical component 114.The optical component 114 can change the direction of the light rays andthen further direct them to the propeller 105. The light rays can thenbe emitted out of the propeller 105 to form a visual indication orsignal that can convey information (e.g., a status of the UAV 100) to anoperator or a bystander. In some embodiments, the optical component 114can change a parameter of the light rays. For example, the opticalcomponent 114 can include a color filter that can change the color ofthe incoming light rays. In some embodiments, the light source 113 canbe non-rotatable (as discussed above) and in other embodiments, thelight source 113 can be rotatable (e.g., can be coupled to the rotorassembly 107).

In some embodiments, the hollow motor assembly 101 can be used in arange finding/scanning system (or a Lidar system). For example, FIG. 1Dis a partially schematic cross-sectional view illustrating first andsecond hollow motor assemblies 101 a, 101 b in a Lidar system 145configured in accordance with representative embodiments of the presenttechnology. The first hollow motor assembly 101 a and the second hollowmotor assembly 101 b are positioned axially adjacent to each other(e.g., along a rotation axis R). The first hollow motor assembly 101 aincludes a first stator assembly 108 a positioned radially external to afirst rotor assembly 107 a. The second hollow motor assembly 101 bincludes a second stator assembly 108 b positioned radially external toa second rotor assembly 107 b. In the illustrated embodiment, thefirst/second hollow motor assemblies 101 a, 101 b are “inner-rotor” typeelectrical motors. In other embodiments, one (or both) of thefirst/second hollow motor assemblies 101 a, 101 b can be an“outer-rotor” type electrical motor. As shown, the Lidar system 145includes a Risley prism pair, which further includes a first prism 114 aand a second prism 114 b. The first prism 114 a is positioned in a firstopening 117 a of the first hollow motor assembly 101 a. The second prism114 b is positioned in a second opening 117 b of the second hollow motorassembly 101 b. The first prism 114 a is coupled to and rotates with thefirst rotor assembly 107 a. The second prism 114 b is coupled to androtates with the second rotor assembly 107 b. By rotating the first andsecond prisms 114 a, 114 b, the Lidar system 145 can perform variousrange finding/scanning tasks. Embodiments of rotating multiple opticalcomponents are further discussed in detail with reference to FIG. 10.

FIG. 2 is an isometric view illustrating components of a hollow motorassembly 201 configured in accordance with representative embodiments ofthe present technology. As shown, the hollow motor assembly 201 includesa rotor assembly 207 having an annular structure. The rotor assembly 207is positioned to rotate about a rotation axis R. The hollow motorassembly 201 also includes a stator assembly 208 positioned external tothe rotor assembly 207. As shown, the stator assembly 208 includes threestator portions 208 a, 208 b, and 208 c. The stator assembly 208 remainsstationary as the rotor assembly 207 rotates. The hollow motor assembly201 includes three bearing assemblies 109 a, 109 b, and 109 c. In theillustrated embodiment, the stator portions 208 a, 208 b, and 208 c andthe bearing assemblies 109 a, 109 b, and 109 c are positioned along acircumference C (of the rotor assembly 207) in a plane P that isgenerally perpendicular to the rotation axis R. In FIG. 2, each of thebearing assemblies 109 a-c is positioned between two of the statorportions 208 a-c. In some embodiments, the hollow motor assembly 201 caninclude different numbers of bearing assemblies and stator portions thanillustrated.

FIG. 3A is a cross sectional view illustrating components of a hollowmotor assembly 301 configured in accordance with representativeembodiments of the present technology. FIG. 3B is a cross-sectional viewalong line A-A of FIG. 3A illustrating components of the hollow motorassembly 301. As shown, the hollow motor assembly 301 includes a rotorassembly 307 having an annular structure (and an annular magnet 320).The rotor assembly 307 is positioned to rotate about a rotation axis R.The hollow motor assembly 301 includes a stator assembly 308 positionedradially external to the rotor assembly 307. As shown, the statorassembly 308 includes two stator portions 308 a and 308 b positionedopposite to each other. The stator assembly 208 remains stationary whenthe rotor assembly 307 rotates. The hollow motor assembly 301 includesfour bearing assemblies 109 a, 109 b, 109 c, and 109 d. In theillustrated embodiment, the stator portions 308 a and 308 b and thebearing assemblies 109 a, 109 b, 109 c, and 109 d are positioned arounda circumference of the rotor assembly 307 in a plane that is generallyperpendicular to the rotation axis R. As shown in FIG. 3A, each of thestator portions 208 a, 208 b is positioned between two of thepositioning components 109 a-d. In other embodiments, the hollow motorassembly 301 can include different numbers of bearing assemblies andstator portions.

As shown in FIG. 3B, the hollow motor assembly 301 includes a guide rail(or protrusion) 315 extending radially outwardly from the rotor assembly307. The guide rail 315 is positioned to facilitate maintaining thelocation (e.g., the axial location) of the bearing assemblies 109 a-drelative to the rotor assembly 107.

FIG. 4A is a top view illustrating components of a hollow motor 401assembly configured in accordance with representative embodiments of thepresent technology. FIG. 4B is a cross-sectional view along line B-B ofFIG. 4A illustrating components of the hollow motor assembly 401. Asshown, the hollow motor assembly 401 includes a rotor assembly 407, astator assembly 408, and a positioning component 409 positioned betweenthe rotor assembly 407 and the stator assembly 408. The rotor assembly407 is positioned to rotate about a rotation axis R. The stator assembly408 is positioned external to the rotor assembly 407 and does notrotate. As shown, the rotor assembly 407 is positioned adjacent to butis rotatable relative to the stator assembly 408. In the illustratedembodiments shown in FIGS. 4A and 4B, the positioning component 409includes multiple rolling balls positioned around a circumference of therotor assembly 407 in a plane generally perpendicular to the rotationaxis R. The positioning component 409 is positioned in the integralhousing that is formed by the rotor assembly 407 and the stator assembly408. As shown, both the rotor assembly 407 and the stator assembly 408have an annular structure. In some embodiments, the positioningcomponent 409 can include an annular structure.

FIG. 4C is a cross-sectional view along line B-B of FIG. 4A illustratinganother embodiment of the hollow motor assembly 401 a. In thisembodiment, the hollow motor assembly 401 a includes a positioningcomponent 409 a which further includes multiple rolling pins positionedaround a circumference of the rotor assembly 407 in a plane generallyperpendicular to the rotation axis R.

FIG. 4D is an isometric, schematic view illustrating components of ahollow motor assembly 401 b configured in accordance with representativeembodiments of the present technology. The hollow motor assembly 401 bincludes a rotor assembly 407 and a stator assembly 408 positionedexternal to the rotor assembly 407. The rotor assembly 407 is positionedto rotate about a rotation axis R relative to the stator assembly 408(which does not rotate). In this embodiment, the hollow motor assembly401 b includes a positioning component 409 b which further includesmultiple rolling balls. As shown, each of the rolling balls ispositioned in a space defined by a support component 417 positionedbetween the rotor assembly 407 and the stator assembly 408. The supportcomponent 417 is configured to maintain the location of the positioningcomponent 409 b relative to the stator assembly 408 and/or the rotorassembly 407.

FIG. 5A is an isometric view illustrating components of a hollow motorassembly 501 a configured in accordance with representative embodimentsof the present technology. As shown, the hollow motor assembly 501 aincludes a rotor assembly 507 having an annular structure. The rotorassembly 507 is positioned to rotate about a rotation axis R. The hollowmotor assembly 501 a includes a stator assembly 508 positioned externalto the rotor assembly 507. As shown, the stator assembly 508 includestwo stator portions 508 a and 508 b positioned opposite to each other.The stator assembly 508 remains stationary when the rotor assembly 507rotates. The hollow motor assembly 501 a includes four bearingassemblies 509 a, 509 b, 509 c, and 509 d (note that the bearingassembly 509 d is not visible in FIG. 5A). In the illustratedembodiment, the stator portions 508 a and 508 b are positioned along acircumference of the rotor assembly 507 in a plane that is generallyperpendicular to the rotation axis R. The bearing assemblies 509 a, 509b, 509 c, and 509 d are positioned along another circumference of therotor assembly 507 in another plane that is generally perpendicular tothe rotation axis R. In other embodiments, the hollow motor assembly 501a can include different numbers of bearing assemblies and/or statorportions than are shown in FIG. 5A. In some embodiments, at least one ofthe stator portions 508 a and 508 b can be positioned axially inalignment with a least one of the bearing assemblies 509 a-d. In otherembodiments, none of the stator portions 508 a and 508 b is positionedaxially in alignment with any one of the bearing assemblies 509 a-d.

FIG. 5B is an isometric view illustrating components of a hollow motorassembly 501 b configured in accordance with representative embodimentsof the present technology. As shown, the hollow motor assembly 501 bincludes a rotor assembly 507 positioned to rotate about a rotation axisR. As shown, the rotor assembly 507 includes a magnet 520 and a magnetyoke 522. The magnet yoke 522 includes an outer portion 507 a and aninner portion 507 b. The inner portion 507 b includes an inner surface516 that circumferentially faces or bounds an interior chamber (orinterior space) 517. The interior chamber or space 517 can be used toaccommodate an optical component (e.g., a lens, a prism, and/or othersuitable devices) and/or a light source. The outer portion 507 a isformed with a recess 518 configured to accommodate the magnet 520 whichhas a flat structure. In some embodiments, the inner portion 507 b ispositioned generally parallel to the rotation axis R, and the outerportion 507 a is portioned generally perpendicular to the rotation axisR.

As shown in FIG. 5B, the hollow motor assembly 501 b includes a statorassembly 508 positioned external to at least a portion (e.g., the innerportion 507 b) of the rotor assembly 507. As shown, the stator assembly508 includes two stator portions 508 a and 508 b positioned opposite toeach other. The stator assembly 508 remains stationary as the rotorassembly 507 rotates. The hollow motor assembly 501 b includes fourbearing assemblies 509 a, 509 b, 509 c, and 509 d (note that the bearingassembly 509 d is not visible in FIG. 5B). In the illustratedembodiment, the stator portions 508 a and 508 b are positioned along afirst circumference of the rotor assembly 507 in a plane that isgenerally perpendicular to the rotation axis R. The bearing assemblies509 a, 509 b, 509 c, and 509 d are positioned along a secondcircumference of the rotor assembly 507 in another plane that isgenerally perpendicular to the rotation axis R. In some embodiments, theradius of the first circumference can be generally the same as theradius of the second circumference.

FIG. 5C is an isometric view illustrating components of a hollow motorassembly 501 c configured in accordance with representative embodimentsof the present technology. The hollow motor assembly 501 c includes arotor assembly 507 positioned to rotate about a rotation axis R. Asshown, the rotor assembly 507 includes a magnet 520 and a magnet yoke522. The magnet yoke 522 includes an outer portion 507 a and an innerportion 507 b. The inner portion 507 b includes an inner surface 516circumferentially faces or bounds an interior chamber 517, which can beused to accommodate a rotatable component (e.g., coupled to the rotorassembly 507) or non-rotatable component (e.g., coupled to anon-rotatable component such as a housing or a chassis). As shown, theouter portion 507 a is formed in flush with the magnet 520 such that therotor assembly 507 has a smooth outer surface 524. In the illustratedembodiment, the magnet 520 is axially positioned between the statorassembly 508 and the outer portion 507 a of the stator assembly 507. Inother embodiments, the magnet 520 can be radially positioned between thestator assembly 508 and the inner portion 507 b of the stator assembly507.

As shown in FIG. 5C, the hollow motor assembly 501 c includes a statorassembly 508 positioned external to at least a portion (e.g., the innerportion 507 b) of the rotor assembly 507. As shown, the stator assembly508 includes two stator portions 508 a and 508 b positioned oppositeeach other. The stator assembly 508 remains stationary as the rotorassembly 507 rotates. The hollow motor assembly 501 c includes fourbearing assemblies 509 a, 509 b, 509 c, and 509 d (note that the bearingassembly 509 d is not visible in FIG. 5B). In the illustratedembodiment, the stator portions 508 a and 508 b and the bearingassemblies 509 a, 509 b, 509 c, and 509 d are positioned along acircumference of the rotor assembly 507 in a plane that is generallyperpendicular to the rotation axis R.

FIG. 5D includes an end view illustrating components of a hollow motorassembly 501 d configured in accordance with representative embodimentsof the present technology. The hollow motor assembly 501 d includes arotor assembly 507 positioned to rotate about a rotation axis R (e.g.,extending perpendicular to the plane in which FIG. 5D is located). Thestator assembly 508 remains stationary as the rotor assembly 507rotates. As shown, the rotor assembly 507 includes an annular structure.The hollow motor assembly 501 d includes a stator assembly 508positioned external to the rotor assembly 507. As shown, the statorassembly 508 includes two sector-stator portions (or arcuate-statorportions) 519 a and 519 b positioned opposite each other. Each of thesector-stator portions 519 a-b includes a stator core portion 526, awinding portion (or winding protrusion) 528 extending form the statorcore portion 526, and a connecting component 530 configured to becoupled to a chassis 523 of the hollow motor assembly 501 d. The chassis523 can be further coupled to other components (e.g., a housing) of thehollow motor assembly 501 d. The winding portions 528 can be used toposition a wire winding component thereon (e.g., by wrapping a wire onthe winding portion 528). In some embodiments, the hollow motor assembly501 d can include multiple bearing assemblies (not shown in FIG. 5D)positioned to maintain the location of the rotor assembly 507 relativeto the stator assembly 508.

FIG. 5E is an isometric view illustrating components of a hollow motorassembly 501 e configured in accordance with representative embodimentsof the present technology. The hollow motor assembly 501 e includes afirst (or lower) rotor/stator set 531, a second (or upper) rotor/statorset 532, and a chassis 533 positioned to couple the first rotor/statorset 531 to the second rotor/stator set 532. The first and secondrotor/stator sets 531, 532 have similar structures and are positioned onopposite sides of the chassis 533. In other embodiments, the first andsecond rotor/stator sets 531, 532 can be coupled by other suitablestructures or means.

As shown in FIG. 5E, each of the first rotor/stator sets 531, 532includes a rotor assembly 507 positioned to rotate about a rotation axisR. As shown, the rotor assembly 507 includes a magnet 520 and a magnetyoke 522 coupled to the magnet 520. The magnet yoke 522 includes anouter portion 507 a and an inner portion 507 b. The inner portion 507 bincludes an inner surface 516 that circumferentially faces or bounds theinterior chamber 517. As shown, the outer portion 507 a is formed with arecess 518 configured to accommodate the magnet 520 which has a flatstructure.

As shown in FIG. 5E, each of the first rotor/stator sets 531, 532includes a stator assembly 508 positioned external to at least a portion(e.g., the inner portion 507 b) of the rotor assembly 507. As shown, thestator assembly 508 includes an annular structure. Embodiments of theannular stator assembly are discussed in further detail below withreference to FIGS. 6A-6C. Each of the first rotor/stator sets 531, 532includes an “annular” bearing assembly 509 (e.g., a set of bearings,rolling balls, rolling pins, and/or other suitable rolling components)that are annularly positioned to maintain the location of the rotorassembly 507 relative to the stator assembly 508. The hollow motorassembly 501 e can be described as an “outer-rotor” type because themagnet 520 is positioned external to the stator assembly 508, eventhough a portion (e.g., the inner portion 507 b) of the rotor assembly507 is positioned internal to the stator assembly 508.

As shown in FIG. 5E, the magnet yoke 522 (e.g., as an integral part ofthe rotor assembly 507) has a structure that can generally cover themagnet 520, the stator assembly 508, and the bearing assembly 509 (e.g.,the structure generally covers the top side, the inner side, and theouter side of these components). In such embodiments, the magnet yoke522 can function as a housing to protect the magnet 520, the statorassembly 508, and the bearing assembly 509. In some embodiments, themagnet yoke 522 can have different structures (e.g., it can cover aportion of other sides of these components).

The first/second rotor/stator sets 531, 532 can be separately controlledsuch that the rotor assemblies 507 of the first/second rotor/stator sets531, 532 can rotate at different rotational speeds. In some embodiments,the rotor assembly 507 of the first rotor/stator set 531 can be coupledto a first optical component (e.g., a first lens or prism), and therotor assembly 507 of the second rotor/stator set 532 can be coupled toa second optical component (e.g., a second lens or prism). The hollowmotor assembly 501 e can further include a light source positionedtherein. By separately controlling the rotor assemblies 507 of the firstand second rotor/stator sets 531, 532 (e.g., at different rotationalspeeds and/or directions, to different angles), the hollow motorassembly 501 e can precisely control the light rays emitted from thelight source that pass through the first/second optical components(e.g., passing through an interior chamber 517 inside the hollow motorassembly 501 e). Embodiments of techniques and devices for controllingthe emitted light rays are discussed below with reference to FIGS.9A-10.

FIGS. 5F, 5G and 5H are schematic diagrams illustrating methods for“pre-positioning” or “pre-tightening” in accordance with representativeembodiments of the present technology. The methods for “pre-positioning”or “pre-tightening” are further discussed in detail below with referenceto FIG. 14. In FIGS. 5F and 5G, hollow motor assemblies 501 f, 501 geach include a rotor assembly 507 positioned to rotate about a rotationaxis R, a stator assembly 508 positioned external to the rotor assembly507, and a bearing assembly 509 positioned to maintain the location ofthe rotor assembly 507 relative to the stator assembly 508. The rotorassembly 507 includes a magnet 520 and a magnet yoke 522 coupled to themagnet 520. The bearing assembly 509 further includes (1) an innerportion 5091 (closer to the rotation axis R) coupled to and configuredto rotate with the rotor assembly 507; (2) an outer portion 5092(farther away from the rotation axis R) positioned radially external tothe inner portion 5091; and (3) a rolling component 5093 rotatablypositioned between the inner portion 5091 and the outer portion 5092. Insome embodiments, the inner portion 5091 and/or the outer portion 5092may be annular or partially annular in shape.

When the bearing assembly 509 is manufactured and before it isinstalled, bearing clearance is typically provided such that componentsof the bearing assembly (e.g., the rolling component 5093) can moveaxially (e.g., with axial clearance) and/or radially (e.g., with radialclearance). However, such clearance can cause movement of the bearingassembly during operation, which in turn can lead to noise, vibration,heat, and other undesirable effects. Such effects can be mitigated by a“pre-positioning” or “pre-tightening” process, in which such bearingclearance can be reduced by causing opposing forces to act upon thebearing assembly.

In FIG. 5F, the magnet 520 is positioned along a direction generallyparallel to the rotation axis R. When an electrical current flows in thestator assembly 508, a magnetic force is created between the magnet 520and the stator component 508. The magnetic force can move the magnet 520toward alignment with the stator component 508 (e.g., as indicated byarrow A1 in FIG. 5F, an edge of the magnet 520 is generally orsubstantially flush with an edge of the stator assembly 508). When themagnet 520 is moved, the coupled magnet yoke 522 is also moved in thesame direction (e.g., as indicated by arrow A2 in FIG. 5F). The magnetyoke 522 is coupled to the inner portion 5091. Accordingly, when themagnet yoke 522 is moved, the inner portion 5091 is also moved (e.g., asindicated by arrow A3 in FIG. 5F). In some embodiments, the innerportion 5091 may be coupled with and hence move with the magnet yoke522, while the outer portion 5092 may not move with the magnet yoke 522(e.g., the outer portion 5092 may be fixedly coupled to the housing or asimilar structure). Thus, when the inner portion 5091 is moved relativeto the outer portion 5092, opposing forces A3 and A4 act upon thebearing assembly 509 along the axial direction, thereby reducing aninternal axial clearance of the rolling component 5093. In other words,the relative movement between the inner portion 5091 and the outerportion 5092 can facilitate positioning the rolling component 5093 atits proper working location (e.g., to reduce an axial clearance of thebearing assembly 509). Accordingly, the rolling component 5093 can bebetter positioned between the inner portion 5091 and the outer portion5092, which can effectively reduce noise or vibration.

In FIG. 5G, the magnet 520 is positioned between the stator assembly 508and the bearing assembly 509, but can still be used to orient thebearing assembly 509. When an electrical current flows in the statorassembly 508, it creates a magnetic force between the magnet 520 and thestator component 508 that can move the magnet 520 toward the statorcomponent 508 (e.g., as indicated by arrow B1 in FIG. 5G, the size of agap G between the between the magnet 520 and the stator component 508 isdecreased). When the magnet 520 is moved, the coupled magnet yoke 522 isalso moved in the same direction (e.g., as indicated by arrow B2 in FIG.5G). The magnet yoke 522 is coupled to the inner portion 5091.Accordingly, when the magnet yoke 522 is moved, the inner portion 5091is also moved (e.g., as indicated by arrow B3 in FIG. 5G). In someembodiments, the inner portion 5091 may be coupled with and hence movewith the magnet yoke 522, while the outer portion 5092 may not move withthe magnet yoke 522 (e.g., the outer portion 5092 may be fixedly coupledto the housing or a similar structure). Thus, when the inner portion5091 is moved relative to the outer portion 5092, opposing forces B3 andB4 act upon the bearing assembly 509 along the axial direction, therebyreducing an internal axial clearance of the rolling component 5093. Inother words, the relative movement between the inner portion 5091 andthe outer portion 5092 can facilitate positioning the rolling component5093 at its proper working location (e.g., to reduce an axial clearanceof the bearing assembly 509). Accordingly, the rolling component 5093can be better positioned between the inner portion 5091 and the outerportion 5092, which can effectively reduce noise or vibration. The“pre-positioning” or “pre-tightening” process described herein can beapplied to other types of bearing assemblies (e.g., the positioningcomponent 109).

In some embodiments, the “pre-positioning” or “pre-tightening” processcan be done by adding two or more additional magnets to a hollow motorassembly. For example, FIG. 5H illustrates methods for “pre-positioning”or “pre-tightening” by additional magnets in accordance withrepresentative embodiments of the present technology. A hollow motorassembly 501 h in FIG. 5H includes first and second rotor/stator sets531,532 (e.g., similar to the motor structure discussed in FIG. 5E).

The first rotor/stator set 531 includes a first connecting member 550Xconfigured to couple with a second connecting member 550Y of the secondrotor/stator set 532. The first rotor/stator set 531 includes a firstrotor assembly 507X coupled to an optical component 514, a first statorassembly 508X positioned radially external to the first rotor assembly507X, a first bearing assembly 509X positioned to maintain the locationof the first rotor assembly 507X relative to the first stator assembly508X, and a first magnet 551X positioned adjacent to the firstconnecting member 550X. The second rotor/stator set 532 includes asecond rotor assembly 507Y, a second stator assembly 508Y positionedradially external to the second rotor assembly 507Y, a second bearingassembly 509Y positioned to maintain the location of the second rotorassembly 507Y relative to the second stator assembly 508Y, and a secondmagnet 551Y positioned adjacent to the second connecting member 550Y. Insome embodiments, the second rotor/stator set 532 can also couple to anoptical component. In the illustrated embodiment in FIG. 5 H, the firstand second bearing assemblies 509X, 509Y both have an annular structure.

The first bearing assembly 509X includes an inner portion 509X1(rotatable; coupled to the first rotor assembly 507X) and an outerportion 509X2 (non-rotatable; coupled to the housing 537). The firstbearing assembly 509X can include one or more rolling component (notshown in FIG. 5H) between the outer portion 509X2 and the inner portion509X1, so as to facilitate the relative rotation between these twocomponents. Similarly, the second bearing assembly 509Y can include anouter portion 509Y2 (non-rotatable; coupled to the housing 537) and aninner portion 509Y1 (rotatable; coupled to the second rotor assembly507Y).

As shown in FIG. 5H, the first and second magnets 551X, 551Y areconfigured to generate a repulsive magnetic force. When the first rotorassembly 507X rotates to a location where the first and second magnet551X, 551Y are axially aligned (as shown in FIG. 5H), the repulsivemagnetic force moves the first magnet 551X and the first connectingmember 550X in direction D1 and moves the second magnet 551Y and thesecond connecting member 551Y in opposite direction D2. As a result, theinner portions 509X2, 509Y2 can be moved by the repulsive magnetic force(e.g., via the first and second rotor assemblies 507X, 507Y and thefirst and second connecting members 550X, 550Y). More particularly, theinner portion 509X1 moves in direction D1, and the inner portion 509Y1moves in direction D2. Opposing forces (in the directions D1 and D2) actupon the first bearing assembly 509X. Similarly, opposing forces (in thedirections D1 and D2) act upon the second bearing assembly 509Y.Accordingly, the first and second bearing assemblies 509X, 509Y can be“pre-positioned” or “pre-tightened” in the ways similar to thosedescribed above with reference to FIGS. 5F and 5G. In some embodiments,the “pre-positioning” or “pre-tightening” methods described above withreference to FIG. 5H can be applied to a hollow motor assembly with asingle rotor/stator set (e.g., the first rotor/stator set 531). Forexample, in such embodiments, the first magnet 551X can be attached tothe first rotor assembly 507X, and the second magnet 551Y can beattached to housing 537 or a chassis attached to the housing 537. Whenthe first magnet 551X and the second magnet 551Y are positioned togenerate a repulsive magnetic force, the bearing assembly 509X can be“pre-positioned” or “pre-tightened” in the ways similar to thosedescribed above.

FIG. 6A is an isometric view illustrating components of a hollow motorassembly 601 configured in accordance with representative embodiments ofthe present technology. The hollow motor assembly 601 includes a rotorassembly 507 having an annular structure. The rotor assembly 507 ispositioned to rotate about a rotation axis R. The hollow motor assembly601 includes an annular stator assembly 608 positioned external to therotor assembly 507. The annular stator assembly 608 includes acontinuous annular structure. The hollow motor assembly 601 includesfour bearing assemblies 509 a, 509 b, 509 c, and 509 d (note that thebearing assembly 509 d is not visible in FIG. 6A). In the illustratedembodiment, the stator assembly 608 is positioned along a firstcircumference of the rotor assembly 507 in a plane that is generallyperpendicular to the rotation axis R. The bearing assemblies 509 a, 509b, 509 c, and 509 d are positioned along a second circumference of therotor assembly 507 in another plane that is generally perpendicular tothe rotation axis R. In the illustrated embodiment in FIG. 6A, theradius of the first circumference is generally the same as the radius ofthe second circumference. In some embodiments, the hollow motor assembly601 can have a positioning assembly having an annular structure.

FIGS. 6B and 6C are isometric views illustrating annular statorassemblies 608 a, 608 b configured in accordance with representativeembodiments of the present technology. As shown in FIG. 6B, the annularstator assembly 608 a includes (1) an annular stator core portion 626,and (2) multiple winding portions (or winding protrusions) 628positioned along and extending inwardly from the stator assembly 608 a.The winding portions 628 can be used to position a wire windingcomponent thereon (e.g., by winding a wire on the winding portion 628).In FIG. 6B, the winding portions 628 are radially positioned (e.g.,toward a rotation axis R). In FIG. 6C, the annular stator assembly 608 bcan include a plurality of (e.g., six) stator segments 634 a-f that arepositioned adjacent to one another in a circumferential direction. InFIG. 6C, the winding portions 628 are axially positioned (e.g.,generally parallel to a rotation axis R).

FIG. 6D is an isometric view illustrating one stator segment 634configured in accordance with representative embodiments of the presenttechnology. As shown, the stator segment 634 can include a main body 635and one or more (e.g., four) protrusions 636 extending from the mainbody 635. In some embodiments, the protrusions 636 can be used toposition winding components thereon. The stator segment 634 can includea hexagonal recess 646 and a hexagonal protrusion 647 on one side (e.g.,the inner side of the stator segment 634). The hexagonal recess 646 isconfigured to fittingly accommodate another hexagonal protrusion 647 (ofanother stator segment 634 positioned next thereto). By thisarrangement, the six stator segments 634 a-f can together form thestator assembly 608 b shown in FIG. 6C. In other embodiments, at leasttwo of the six stator segments 634 a-f can be coupled by glue or othersuitable means. In some embodiments, the stator segment 634 can be madeby winding components (e.g., wire windings).

FIG. 7A is a top view illustrating components of a hollow assembly 701 aconfigured in accordance with representative embodiments of the presenttechnology. The hollow assembly 701 a includes a housing 737 and a rotorassembly 707 positioned in the housing 737. The rotor assembly 707 ispositioned to rotate about a rotation axis R. The hollow assembly 701 afurther includes four positioning components 709 a-d positioned at thefour corners of the housing 737 and external to the rotor assembly 707.The positioning components 709 a-d can rotate relative to the rotorassembly 707 and maintain the (radial) location of the rotor assembly707. At least one of the positioning components 709 a-d can be coupledto a driving assembly (e.g., an electrical motor). The driving assemblyprovides torque to rotate the positioning components 709 a-d and therotator assembly 707.

FIG. 7B is an isometric view illustrating components of a hollowassembly 701 b configured in accordance with representative embodimentsof the present technology. The hollow assembly 701 b includes a firstrotor assembly 707 a, a second rotor assembly 707 b, a first positioningcomponent 709 a, a second positioning component 709 b, and a drivingassembly 708 (e.g., an electrical motor). The first/second rotorassemblies 707 a, 707 b are both positioned to rotate about a commonrotation axis R. The first positioning component 709 a is rotatablycoupled to and positioned external to the first rotor assembly 707 a.The first positioning component 709 a can rotate relative to the firstrotor assembly 707 a and maintain the location thereof. The secondpositioning component 709 b is rotatably coupled to and positionedexternal to the second rotor assembly 707 b. The second positioningcomponent 709 b can rotate relative to the second rotor assembly 707 band maintain the location thereof. As shown, both the first/secondpositioning components 709 a, 709 b are coupled to and driven by thedriving assembly 708 (e.g., the first and second positioning components709 a, 709 b are positioned coaxially along an axial direction A). Inother embodiments, the first and second positioning components 709 a,709 b can be driven by separate driving assemblies. In some embodiments,the first and second positioning components 709 a, 709 b can bepositioned differently (e.g., non-coaxially). In the illustratedembodiment, the first positioning component 709 a is a first gear (e.g.,having a first number of gear teeth) and the second positioningcomponent 709 b is a second gear (e.g., having a second number of gearteeth) different than the first gear. Because the first gear may have aconfiguration different than the second gear (e.g., a different numberof teeth), the driving assembly 708 can rotate the first/second rotorassemblies 707 a, 707 b at different rotational speeds. In someembodiments, a first optical component can be positioned inside andfixedly coupled to the first rotor assembly 707 a and a second opticalcomponent can be positioned inside and fixedly coupled to the secondrotor assembly 707 b. In such embodiments, the driving assembly 708 canrotate the first/second optical components at different rotationalspeeds.

FIG. 7C is an isometric view illustrating components of another hollowassembly 701 c configured in accordance with representative embodimentsof the present technology. The hollow assembly 701 c includes a firstrotor assembly 707 a, a second rotor assembly 707 b, a first positioningcomponent 709 a, a second positioning component 709 b, and a drivingassembly 708. The first/second rotor assemblies 707 a, 707 b are bothpositioned to rotate about a rotation axis R. The first positioningcomponent 709 a is positioned external to and coupled with the firstrotor assembly 707 a via a first belt 738 a. The first positioningcomponent 709 a can rotate with the first rotor assembly 707 a andmaintain the location thereof. The second positioning component 709 b ispositioned external to and coupled with the second rotor assembly 707 bvia a second belt 738 b. The second positioning component 709 b canrotate with the second rotor assembly 707 b and maintain the locationthereof. As shown, both the first/second positioning components 709 a,709 b are coupled to and driven by the driving assembly 708. In theillustrated embodiment, the first positioning component 709 a and thesecond positioning component 709 b have a similar size/shape. Therefore,the driving assembly 708 can rotate the first/second rotor assemblies707 a, 707 b at the same rotational speed. In other embodiments, thefirst positioning component 709 a and the second positioning component709 b can have different sizes/shapes such that the driving assembly 708can rotate the first/second rotor assemblies 707 a, 707 b at differentrotational speeds. In some embodiments, a first optical component can bepositioned inside and fixedly coupled to the first rotor assembly 707 aand a second optical component can be positioned inside and fixedlycoupled to the second rotor assembly 707 b. In such embodiments, thedriving assembly 708 can also rotate the first/second opticalcomponents.

FIG. 8 is a top view illustrating components of a hollow assembly 801configured in accordance with representative embodiments of the presenttechnology. The hollow assembly 801 includes a housing (or a ring gear)837, a rotor assembly (or a sun gear) 807, a chassis (or a planetarycarrier) 840, and four positioning components (or planetary pinions) 809a-d rotatably coupled to the chassis 840. The chassis 840 can be fixedand not rotatable. The rotor assembly 807 is positioned internal to thepositioning components 809 a-d, the chassis 840, and the housing 837.The rotor assembly 807 can rotate with respect to a rotation axis R. Atleast one of the positioning components 809 a-d can be coupled to adriving assembly (e.g., an electrical motor). The driving assemblyprovides torque to rotate the positioning components 809 a-d. When thepositioning components 809 a-d are rotated, the rotor assembly 807 andthe housing 837 are also rotated. The positioning components 809 a-d canmaintain the relative locations of the rotor assembly 807 and thehousing 837 when they are rotated. In some embodiments, a first opticalcomponent can be coupled to and rotate with the rotor assembly 807, anda second optical component can be coupled to and rotate with the housing837.

FIG. 9A is a schematic diagram illustrating components of a hollow motorassembly 901 configured in accordance with representative embodiments ofthe present technology. In the illustrated embodiments, the hollow motorassembly 901 is configured to drive an optical component 914 positionedtherein. As shown, the hollow motor assembly 901 further includes ahousing 937, a rotor assembly 907, a stator assembly 908 positionedexternal to the rotor assembly 907, a positioning component 909, and alight source 913 (e.g., a range finding/scanning component/sensor or alight source for a Lidar system). The positioning component 909 ispositioned between the stator assembly 908 and the rotor assembly 907 tomaintain a location of the rotor assembly 907 relative to the statorassembly 908. As shown, the stator assembly 908 is fixedly attached tothe housing 937. The stator assembly 908 is positioned radially externalto and coaxially with the rotor assembly 907 (relative to a rotationaxis R). The rotor assembly 907 can rotate relative to the statorassembly 908. In the illustrated embodiment, the optical component 914is coupled to and rotates with the rotor assembly 907. By thisarrangement, the optical component 914 can corporate with the lightsource 913 to adjust the directions of the light rays (as indicated byarrows in FIG. 9A) from the light source 913 (so as to perform ascanning or range-finding task).

For example, at a first time point, the light ray from the light source913 passes through the optical component 914 and the optical component914 changes its direction from arrow T to arrow T1 (e.g., the opticalcomponent 914 has an asymmetric shape so it can change the direction ofincoming light rays). From the first time point to a second time point,the optical component 914 has been rotated. At the second time point,the light ray from the light source 913 passes through the opticalcomponent 914 and the optical component 914 changes its direction fromarrow T to arrow T2. As a result, the optical component 914 can adjustthe directions of the light rays from the light source 913.

In some embodiments, the hollow motor assembly 901 can also beconfigured to drive a propeller 105 (of a UAV). As indicated by dashedlines, the hollow motor assembly 901 can be coupled to the propeller105, which includes a first blade 110, a second blade 111 opposite tothe first blade 110, and a hub 112. When the rotor assembly 907 rotates,the propeller 105 rotates with it.

As shown, the rotor assembly 907 has an inner surface 916 thatcircumferentially faces or bounds an interior chamber (or interiorspace) 917. The interior chamber 917 can be used to accommodate theoptical component 914. The optical component 914 is fixedly coupled tothe rotor assembly 907. In some embodiments, the optical component 914and the rotor assembly 907 can be coupled by a mechanical mechanism(e.g., a connecting component, a screw, a bolt, a nail, a paired recessand protrusion, a wedge, and/or other suitable mechanisms). In someembodiments, the optical component 914 and the rotor assembly 907 can becoupled with/using glue. When the rotor assembly 907 rotates, theoptical component 914 rotates with it. Examples of the optical component914 include a lens, a prism, or a combination thereof.

As shown in FIG. 9A, the light source 913 can be positioned at thecenter of the hollow motor assembly 901 (e.g., on the rotation axis R).In some embodiments, the light source 913 can be positioned at otherlocations in the housing 937 (e.g., off the rotation axis R). In otherembodiments, the light source 913 can be fixedly attached to (an innersurface of) the housing 937. In some embodiment, the light emitted fromthe light source can be collimated or adjusted before it reaches theoptical component 914.

In the embodiments where the hollow motor assembly 901 is coupled to thepropeller 105, the light source 913 can emit light rays to the propeller105 through the optical component 914. The optical component 914 canchange the directions of the light rays (as indicated by arrows in FIG.9A) and then further direct them to the propeller 105. By rotating theoptical component 914 and the rotor assembly 907, the directions of thelight rays can be controlled. Accordingly, the incoming angles of thelight rays can be controlled when the light rays enter into thepropeller 105. By so doing, the light rays emitted from the propeller105 can accordingly be controlled.

For example, in response to receiving the incoming light rays withdifferent incoming angles, the propeller 105 can accordingly generatevarious visual indications (e.g., by redirecting/reflecting the lightrays with different incoming angles). In some embodiments, the propeller105 can include a light guide structure, which further includes: (1) alight entrance portion configured/positioned to receive a light ray fromthe hollow motor assembly 901; (2) a light transmission portionconfigured/positioned to transmit the light ray; and (3) a light exitportion configured/positioned to direct the light ray toward a target(e.g., an operator, a bystander, and/or a target surface) in one or moredirections. In some embodiments, the visual indication can include anouter contour of the propeller 105 or a UAV. In some embodiments, thevisual indication can be indicative of a location of a UAV (or thelocation of a UAV component). In some embodiments, the visual indicationcan be indicative of a status/parameter of a UAV (e.g., traveldirection, orientation, and/or flight status).

FIGS. 9B and 9C are isometric views illustrating optical component 914a, 914 b configured in accordance with multiple embodiments of thepresent technology. As shown in FIG. 9B, one optical component 914 a canhave an elliptical-cylinder shape. As shown in FIG. 9C, another opticalcomponent 914 b can have an elliptical-wedge shape. In otherembodiments, the optical components can be formed as a cylinder or canhave other suitable shapes. Both the optical components 914 a, 914 b canhave a first surface 941 and a second surface 942 opposite to the firstsurface 941. In the illustrated embodiment, the first surface 941 andthe second surface 942 are not generally parallel to each other. Inother embodiments, the first surface 941 and the second surface 942 canbe generally parallel to each other. In the illustrated embodiment, thefirst surface 941 and the second surface 942 are both flat surfaces. Inother embodiments, however, one or both of the first/second surfaces941, 942 can be a curved surface (e.g., as the dashed lines shown inFIG. 10), a rough surface, a teethed surface, or a combination thereof.For example, when a user wants to focus light rays, the user can choosea convex optical component with one or two curved surfaces. As anotherexample, when a user needs to diffuse light rays, the user can select anoptical component with one or two teethed/rough surfaces.

FIG. 10 is a schematic diagram illustrating the use of multiple opticalcomponents in accordance with embodiments of the present technology. Thepresent technology can be used to change/control the light pathways ofmultiple light rays that pass through the multiple optical components.The ability to control the light pathways is important in certaintechnical fields such as distance measurement by emitting/receivinglaser beams. As shown in FIG. 10, a light source 913, a first opticalcomponent 914 c and a second optical component 914 d are positionedalong a rotation axis R. The first optical component 914 c and thesecond optical component 914 d can rotate at different rotational speedsand/or directions. For example, the first optical component 914 c can befixedly coupled to a first rotor assembly, and the second opticalcomponent 914 d can be fixedly coupled to a second rotor assembly. Thefirst/second rotor assemblies can be independently controlled/rotated.The light source 913 can direct a light ray to the first opticalcomponent 914 c along the rotation axis R (indicated as D1 in FIG. 10).The first optical component 914 c then changes the direction of theincoming light ray from D1 to D2. The second optical component 914 dthen further changes the direction of the incoming light ray from D2 toD3. By rotating the first optical component 914 c and the second opticalcomponent 914 d, a user can precisely control the direction of the lightray emitted from the light source 913. (To clarify, in such embodiments,the first/second rotor assemblies are only used to rotate thefirst/second optical components 914 c, 914 d, and are not used to rotatea propeller.)

The optical components described above may have asymmetric shapes. Whenrotated, these components may be unbalanced. Particular embodiments ofthe present technology can address this potential issue. For example,FIGS. 11A and 11B are schematic diagrams illustrating counterweights1143, 1144 configured in accordance with representative embodiments ofthe present technology. In FIGS. 11A and 11B, an optical component 1114is fixedly coupled to a rotor assembly 1107. The optical component 1114and the rotor assembly 1107 are positioned to rotate together about arotation axis R. As shown, the optical component 1114 has an asymmetricshape. After a rotation-balance analysis (discussed below with referenceto FIG. 12), the shapes, materials, and/or weights of the counterweights1143, 1144 can be determined. The locations to position or install thecounterweights 1143, 1144 can also be determined. As shown in FIG. 11A,the counterweight 1143 can be a counterweight block fixedly attached tothe inner surface of the rotor assembly 1107. In FIG. 11B, thecounterweight 1144 can be glue attached to the inner surface of therotor assembly 1107. The optical component 1114 in FIG. 11B can have abetter light transmission rate than the optical component 1114 in FIG.11A, at least because the counterweight 1144 blocks less light passagethan does the counterweight 1143. In some embodiments, thecounterweights 1143, 1144 can be made of materials with differentdensities. In some embodiments, to enhance the light transmission rateof the optical component 1114, the shapes, transparency, or othersuitable parameters of the counterweights 1143, 1144 can also beconsidered. In other embodiments, the counterweights 1143, 1144 can bepositioned in other locations such as an edge or a peripheral portion ofthe rotor component 1107. In some embodiments, the numbers of thecounterweights 1143, 1144 can vary.

In some embodiments, instead of adding a counterweight, the opticalcomponent 1114 can be balanced by removing a portion thereof. In someembodiments, the optical component 1114 can be reshaped so as to balanceits rotation. In some embodiments, the rotor assembly 1107 can bebalanced in similar ways, alone or in conjunction with balancing theoptical component 1114.

FIG. 12 is a schematic diagram illustrating a rotation-balance analysisfor an optical component 1214 configured in accordance withrepresentative embodiments of the present technology. As shown, theoptical component 1214 has an asymmetric shape and therefore it may notrotate in a balanced manner about a rotation axis Z. The presenttechnology provides a method for effectively and efficiently determininghow to balance an optical component having an asymmetric shape. Themethod is based in part on the mass and the density of the opticalcomponent.

First, the method includes calculating the product of the mass (in) anda radius vector (r) for each layer of the optical component, based onthe integral Equation (A) below:

P _(Z)=∫∫_(s) ρ{right arrow over (r)}dS  (A)

In Equation (A) above, “P_(Z)” represents the “unbalance” value at levelZ, “S” represents the cross-sectional area of level Z, “ρ” representsthe density of the optical component at level Z, and “{right arrow over(r)}” represents radius vector.

The method then decomposes the calculated product value to two or morelevels. For example, as shown in FIG. 12, the calculated product valuecan be decomposed to level Z₁ and Z₂, according to Equations (B) and (C)below.

$\begin{matrix}{P_{1} = {\int{\int{\int_{v}{\frac{Z - Z_{2}}{Z_{1} - Z_{2}}\rho \overset{\rightarrow}{r}{dV}}}}}} & (B) \\{P_{2} = {\int{\int{\int_{v}{\frac{Z_{1} - Z}{Z_{1} - Z_{2}}\rho \overset{\rightarrow}{r}{dV}}}}}} & (C)\end{matrix}$

In Equations (B) and (C) above, “P₁” represents the “unbalance” value atlevel Z₁, “P₂” represents the “unbalance” value at level Z₂, “V”represents the volume of the optical component, “Z” is the heightvariable, “ρ” represents the density of the optical component at levelZ, and “{right arrow over (r)}” represents the radius vector. Based onEquations (A), (B) and (C) above, a user can determine the “unbalance”amount (e.g., how much weight to be added) to be added (or removed, insome embodiments) at specific levels (e.g., levels Z₁ and Z₂).

Below is an example showing how the “unbalance” value can be calculatedfor a prism having a right-triangle cross-section. Assume that theheight of the prism is “H” and the radius of the prism is “r,” and thenthe “unbalance” value “P_(Z0)” at level Z₀ can be calculated as follows:

dP _(Z0)=∫∫_(S){right arrow over (r _(xy))}dm=∫∫ _(s)(x·{right arrowover (l)}+y·{right arrow over (j)})dm=0·{right arrow over (l)}+∫∫ _(s)y·ρdxdydz₀ ·{right arrow over (j)}  (D)

In Equation (D) above, “S” represents the (cross-sectional) area oflevel Z₀, which can be defined by the circle “x²+y²=R²” and the line“y=y₀.” “{right arrow over (r_(xy))}” represents the radius vector frompoint (x, y) to the rotation axis of the prism. “ρ” represents thedensity of the prism. The “unbalance” value at level Z₀ can be furthercalculated based on Equations (E), (F), and (G) below.

$\begin{matrix}{{dP_{z0}} = {{\int_{- \sqrt{R^{2} - y^{2}}}^{\sqrt{R^{2} - y^{2}}}{dx{\int_{- R}^{y_{0}}{\rho ydydz_{0}}}}} = {\rho \frac{2}{3}\left( {R^{2} - y_{0}^{2}} \right)^{\frac{3}{2}}dz_{0}}}} & (E) \\{y_{0} = {{- \frac{2R}{H}}z_{0}}} & (F) \\{{dP_{z0}} = {\rho \frac{2}{3}\left( {R^{2} - \frac{4R^{2}z_{0}^{2}}{H^{2}}} \right)^{\frac{3}{2}}dz_{0}}} & (G)\end{matrix}$

The method can further decompose the “unbalance” value to two levels,“Z=H/2” and “Z=−H2.” The method can then integrally calculate the“unbalance” values for all levels “Z=Z₀” As a result, the “unbalance”values at these two levels (P₁ and P₁₁) can be calculated based onEquations (H), (I), (J), and (K) below.

$\begin{matrix}{{dP}_{1} = {\frac{\frac{H}{2} + z_{0}}{H} \cdot {dP}_{z\; 0}}} & (H) \\{{dP}_{11} = {\frac{\frac{H}{2} - z_{0}}{H} \cdot {dP}_{z\; 0}}} & (I) \\{P_{1} = {{\int_{- \frac{H}{2}}^{\frac{H}{2}}{dP}_{1}} = {\frac{\pi \; \rho}{16}{HR}^{3}}}} & (J) \\{P_{11} = {{\int_{- \frac{H}{2}}^{\frac{H}{2}}{dP}_{11}} = {\frac{\pi \; \rho}{16}{HR}^{3}}}} & (K)\end{matrix}$

FIG. 13 is a flowchart illustrating embodiments of a method 1300 formanufacturing (or assembling) a hollow motor apparatus in accordancewith representative embodiments of the present technology. At block1301, the method 1300 includes performing a rotation-balance analysis onan optical component to generate an analysis result. Embodiments of therotation-balance analysis can be found in the descriptions above withreference to FIG. 12. The analysis result shows a user whether theoptical component needs to be balanced. At block 1303, the method 1300can include weight-balancing the optical component at least partiallybased on the result of the analysis. In some embodiments, acounterweight (e.g., a weight block, glue, and/or other suitableweights) can be coupled to the optical component to balance the opticalcomponent. In some embodiments, a portion of the optical component canbe removed so as to balance the optical component. In some embodiments,the optical component can be reshaped to be balanced. Embodiments of thebalance process can be found in the descriptions above with reference toFIG. 11.

At block 1305, the method 1300 includes positioning the opticalcomponent in an interior chamber defined at least in part by an innerportion of a rotor assembly. Embodiments of the interior chamber includeinterior chambers 117, 517, and 917 discussed above. At block 1307, themethod 1300 includes coupling the optical component to the rotorassembly. At block 1309, the rotor assembly is rotatably coupled to apositioning component. In some embodiments, the positioning componentcan be a bearing assembling. In some embodiments, the positioningcomponent can be a bearing, gear, puller, a roller, and/or othersuitable components. At block 1311, the positioning component isrotatably coupled to a stator assembly. The positioning component ispositioned external to the inner portion of the rotor assembly tomaintain a location of the rotor assembly relative to the statorassembly.

FIG. 14 is a flowchart illustrating embodiments of a method 1400 forpre-positioning a bearing assembly in a hollow motor apparatus inaccordance with representative embodiments of the present technology.The hollow motor apparatus includes a rotor assembly having a rotationaxis and a stator assembly coaxially positioned adjacent to the rotorassembly. The bearing assembly is configured to maintain the location ofthe rotor assembly relative to the stator assembly. The bearing assemblyincludes (1) an inner portion coupled to the rotor assembly, (2) anouter portion positioned axially external to the inner portion, and (3)more than one rolling component rotatably positioned between the innerportion and the outer portion. Embodiments of the inner portion, theouter portion, and the rolling component are discussed in detail withreference to FIGS. 5F and 5G. At block 1401, the method 1400 includescausing generation of a magnetic force between the stator assembly andthe rotor assembly. At block 1403, the method includes causing relativemovement between the inner portion of the bearing assembly and the outerportion of the bearing assembly, via the magnetic force, to reduce abearing clearance of the bearing assembly.

As discussed above, aspects of the present technology provide animproved hollow motor assembly that enables a user to position anoptical component therein such that the component can rotate with arotor assembly of the hollow motor assembly. The rotor assembly can becoupled to and rotate a propeller of a UAV. In addition to driving thepropeller, the hollow motor assembly can also illuminate the propellerby having a light source positioned therein. The propeller can receivelight from the light source (the light passes through the rotatableoptical component), and then generate a visual indication to conveyinformation (e.g., a status) associated with the UAV to an operator.Accordingly, the operator can effectively learn the information (e.g.,orientation, location, flight status, and/or other suitable status) ofthe UAV in a straight-forward manner. It is especially helpful forunsophisticated or relatively new UAV operators, at least because thediscussed technology can help them properly control the UAV. Anotheradvantage includes that the hollow motor assembly can have a compactdesign. Accordingly, it can be implemented in a traditional UAV bysimply replacing a traditional motor assembly by the hollow motorassembly of the present technology, without requiring extra space forinstallation.

The present technology also provides a hollow apparatus that can includemultiple hollow, annular structures that can independently rotate. Eachannular structure can be coupled to a corresponding optical componentand rotate the same. In particular embodiment, the hollow apparatus canbe implemented as a laser distance-measuring device. That device caninclude a laser light source positioned therein and configured to emitlaser rays, through the optical components, to a target surface. By (1)directing the laser rays to pass the optical components and (2)controlling the rotation of the optical components, the device cangenerate various desirable laser rays (e.g., focused, parallel, in aparticular direction, and/or other suitable characteristics) that can beused to measure different types of target surfaces (e.g., rough, smooth,teethed, angled or a combination thereof). It is also advantageous thatthe device can have a compact design, such that a user can carry it orit can be easily installed in other devices (e.g. a vehicle or UAV).

From the foregoing, it will be appreciated that specific embodiments ofthe technology have been described herein for purposes of illustration,but that various modifications may be made without deviating from thetechnology. For example, particular embodiments were described above inthe context of a hollow motor apparatus. In other embodiments, thepresent technology can be implemented by other suitable rotatable hollowannular structure (e.g., a laser emitter with a hollow annularstructure). The hollow motor assemblies can include different numbers ofstator portions, bearing assemblies, and/or other elements that arespecifically illustrated herein.

Further, while advantages associated with certain embodiments of thetechnology have been described in the context of those embodiments,other embodiments may also exhibit such advantages, and not allembodiments need necessarily exhibit such advantages to fall with withinthe scope of the present technology. Accordingly, the present disclosureand associated technology can encompass other embodiments not expresslyshown or described herein.

At least a portion of the disclosure of this patent document containsmaterial which is subject to copyright protection. The copyright ownerhas no objection to the facsimile reproduction by anyone of the patentdocument or the patent disclosure, as it appears in the Patent andTrademark Office patent file or records, but otherwise reserves allcopyright rights whatsoever.

1. A hollow motor apparatus, comprising: a rotor assembly configured forrotation about a rotation axis, the rotor assembly having an innerportion disposed around an opening that is configured to receive atleast a portion of a payload and to rotate the payload; a statorassembly positioned adjacent to the rotor assembly and coaxially withthe rotor assembly relative to the rotation axis; and a bearing assemblydisposed outside of the inner portion of the rotor assembly and operablycoupled to the rotor assembly, the bearing assembly configured tomaintain a position of the rotor assembly relative to the statorassembly.
 2. The apparatus of claim 1, wherein the payload comprises anoptical component configured for rotation with the rotor assembly aboutthe rotation axis, the optical component comprising at least one of aprism or a reflector. 3-31. (canceled)
 32. The apparatus of claim 1,wherein the stator assembly is arranged within a first plane that issubstantially perpendicular to the rotation axis, and wherein thebearing assembly is arranged within a second plane that is substantiallyperpendicular to the rotation axis, the second plane being differentfrom the first plane.
 33. (canceled)
 34. The apparatus of claim 32,wherein the rotor assembly comprises: a magnet yoke and a magnet coupledto the magnet yoke, wherein the magnet yoke comprises a portion incontact with the bearing assembly, and wherein the magnet is positionedeither radially internal to the stator assembly, external to the magnetyoke, between the stator assembly and the bearing assembly, or betweenthe magnet yoke and the bearing assembly. 35-61. (canceled)
 62. Theapparatus of claim 1, wherein the bearing assembly comprises: an innerportion coupled to the rotor assembly and surrounding the inner portionof the rotor assembly; an outer portion positioned radially external tothe inner portion of the bearing assembly; and at least one rollingcomponent rotatably positioned between the inner portion of the bearingassembly and the outer portion of the bearing assembly. 63-82.(canceled)
 83. A system, comprising: the hollow motor apparatus of claim1; and a second hollow motor apparatus comprising: a second rotorassembly configured for rotation about a second rotation axis, thesecond rotor assembly having an inner portion disposed around an openingthat is configured to receive at least a portion of a payload; a secondstator assembly positioned adjacent to the second rotor assembly andcoaxially with the second rotor assembly relative to the second rotationaxis; and a second bearing assembly disposed outside of the innerportion of the second rotor assembly and operably coupled to the secondrotor assembly, the second bearing assembly configured to maintain aposition of the second rotor assembly relative to the second statorassembly, wherein the hollow motor apparatus and the second hollow motorapparatus are positioned adjacent to one another.
 84. The system ofclaim 83, wherein the hollow motor apparatus and the second hollow motorapparatus have a common rotation axis. 85-113. (canceled)
 114. A methodfor positioning a bearing assembly in a hollow motor apparatus, thehollow motor apparatus comprising: a rotor assembly configured forrotation about a rotation axis, and a stator assembly positionedadjacent to the rotor assembly and coaxially with the rotor assemblyrelative to the rotation axis, the bearing assembly comprising: an innerportion coupled to the rotor assembly, an outer portion positionedradially external to the inner portion of the bearing assembly, and atleast one rolling component rotatably positioned between the innerportion of the bearing assembly and the outer portion of the bearingassembly, wherein the method comprises: attaching the outer portion ofthe bearing assembly to a support; and applying a force to the innerportion of the bearing assembly along a direction parallel to therotation. 115-118. (canceled)
 119. The apparatus of claim 1, wherein thebearing assembly comprises: an inner portion; an outer portionpositioned radially external to the inner portion of the bearingassembly; and at least one rolling component rotatably positionedbetween the inner portion of the bearing assembly and the outer portionof the bearing assembly, wherein the inner portion of the bearingassembly and the outer portion of the bearing assembly are configured tomove in opposite directions when electrical current flows in the statorassembly.
 120. The apparatus of claim 119, wherein the rotor assemblycomprises a magnet, at least one of the inner portion of the bearingassembly or the outer portion of the bearing assembly being coupled tothe rotor assembly, and wherein when the electrical current flows in thestator assembly: the inner portion of the bearing assembly and the outerportion of the bearing assembly are configured to be driven in theopposite directions, and the magnet is configured to move toward thestator assembly along the rotation axis.
 121. The apparatus of claim 1,wherein the stator assembly and the bearing assembly are configured tosurround the rotor assembly when the stator assembly and bearingassembly are arranged side by side.
 122. The apparatus of claim 2,further comprising: a second optical component configured to rotateabout the rotation axis, wherein the optical component is configured torotate about the rotation axis at a first rotational speed and thesecond optical component is configured to rotate about the rotation axisat a second rotational speed that is different from the first rotationalspeed.
 123. The apparatus of claim 62, further comprising: a chassiscoupled to the outer portion of the bearing assembly, wherein the statorassembly is fixedly coupled to a housing and the chassis is fixedlycoupled to the housing
 124. The apparatus of claim 123, wherein theinner portion of the bearing assembly is configured to be driven into apredetermined position by a force along the rotation axis.
 125. Theapparatus of claim 123, further comprising: a first magnet coupled tothe inner portion of the bearing assembly; and a second magnet facingthe first magnet, wherein the bearing assembly is configured to bedriven into a predetermined position by a magnetic force generatedbetween the first magnet and the second magnet.
 126. The system of claim83, further comprising: a first magnet coupled with the rotor assemblyof the hollow motor apparatus; and a second magnet coupled with thesecond rotor assembly of the second hollow motor apparatus, the secondmagnet facing the first magnet, wherein the first magnet and secondmagnet are configured to position the bearing assembly of the hollowmotor apparatus and the second bearing assembly of the second hollowmotor apparatus in a predetermined configuration.
 127. The system ofclaim 126, wherein the first magnet and the second magnet are configuredto respectively apply opposing forces on the inner portion of the hollowmotor apparatus and the inner portion of the second hollow motorapparatus.
 128. The apparatus of claim 83, wherein the rotor assemblyand the second rotor assembly are configured to rotate at one or more ofdifferent speed or different directions.
 129. The apparatus of claim 83,wherein the rotor assembly is configured to rotate a first light bendingelement, and wherein the second rotor assembly is configured to rotate asecond light bending element.
 130. The apparatus of claim 129, whereinthe first light bending element is a first prism, and the second lightbending element is a second prism or a reflector.